Received November 8, 2017; Revision received December 5, 2017
Noncoding RNAs play essential roles in genetic regulation in all
organisms. In eukaryotic cells, many small noncoding RNAs act in
complex with Argonaute proteins and regulate gene expression by
recognizing complementary RNA targets. The complexes of Argonaute
proteins with small RNAs also play a key role in silencing of mobile
genetic elements and, in some cases, viruses. These processes are
collectively called RNA interference. RNA interference is a powerful
tool for specific gene silencing in both basic research and therapeutic
applications. Argonaute proteins are also found in prokaryotic
organisms. Recent studies have shown that prokaryotic Argonautes can
also cleave their target nucleic acids, in particular DNA. This
activity of prokaryotic Argonautes might potentially be used to edit
eukaryotic genomes. However, the molecular mechanisms of small nucleic
acid biogenesis and the functions of Argonaute proteins, in particular
in bacteria and archaea, remain largely unknown. Here we briefly review
available data on the RNA interference processes and Argonaute proteins
in eukaryotes and prokaryotes.
KEY WORDS: Argonaute proteins, RNA interference, small RNAs,
mobile genetic elements